It would be beneficial to the TPV industry to have a TPV with ultra-fine morphology while still maintaining or preferably exceeding the desirable properties of the dynamic vulcanization in an extruder as mentioned above. It would also be advantageous for the TPV production to be performed in conjunction with the elastomer production without the need to finish and re-dissolve the elastomers. This invention addresses these needs.
GB Patent 1,599,164 discusses the blending of polypropylene (PP) and EPDM in solution. There is no mention of the addition of curatives to enhance physical properties.
A process for producing TPVs is disclosed in U.S. Pat. No. 6,388,016, in which a polymer blend is produced by solution polymerization in series reactors employing metallocene catalysts and the resultant blend is subjected to dynamic vulcanization.
U.S. Pat. No. 6,245,856 describes the use of a compatibilizer in a PP/EPDM thermo plastic olefin (TPO). In the absence of a compatibilizer, the elastomer dispersion is uneven, with some particles greater than 5 micrometers in size. In the presence of the compatibilizer, the dispersion displayed a particle size of about 1 micrometer.
U.S. Pat. No. 6,579,944 discloses a PP/EPDM based TPV composition with a majority of the particles less than 5 micrometers in size, some as large as 10 micrometers, others less than 0.1 micrometers.
U.S. Pat. No. 4,311,628 provides an example of a PP/EPDM based TPV having an EPDM content of 85% by weight. The disclosure states that the TPV is processable as a thermoplastic polymer.
U.S. Pat. No. 6,498,214 discloses thermoplastic polyolefin blend compositions useful for soft touch TPO applications which comprise, in weight percent based upon the weight of components A and B. A is about 99 to about 1 percent of at least one polypropylene homopolymer or copolymer; and B is about 99 to about 1 percent of at least one homogeneously branched ethylene/alpha-olefin copolymer in which the alpha-olefin contains at least 4 carbon atoms and the homogeneously branched copolymer has a crystallinity of less than about 3 percent.
U.S. Ser. No. 60/693,030 filed Jun. 22, 2005, discloses a heterogeneous polymer blend.
Other references of interest include: U.S. Pat. No. 3,629,212, U.S. Pat. No. 4,016,342, U.S. Pat. No. 4,306,041, U.S. Pat. No. 6,245,856, U.S. Pat. No. 6,207,756, U.S. Pat. No. 6,319,998, U.S. Pat. No. 6,770,714,U.S. Pat. No. 4,130,535, U.S. Pat. No. 4,311,628, U.S. Pat. No. 6,388,016, and Wu, Souheng, Phase Structure in Polymer Blends: a Criterion for Rubber Toughening, POLYMER, (1985) 26 (12), 1855-63.
In addition, this invention is related to U.S. Ser. No. 60/693,030, filed Jun. 22, 2005, U.S. Ser. No. 11/296,842, filed Dec. 7, 2005, U.S. Ser. No. 11/296,830, filed Dec. 7, 2005, U.S. Ser. No. 11/295,927, filed Dec. 7, 2005, U.S. Ser. No. 11/295,930, filed Dec. 7, 2005, U.S. Ser. No. 60/699,663, filed Jul. 15, 2005.